Prediction of fracture lines of the calcaneus using a three-dimensional finite element model.

The various lines of calcaneal fractures indicate their complex nature and make their treatment challenging. There is still much debate regarding the position and direction of these fracture lines, even for the primary fracture line. The computed tomography-based finite element model is known to provide accurate predictions of fracture loads and virtual fracture locations for the femur and distal radius. This study aimed to establish how to predict the calcaneus fracture lines using the computed tomography-based finite element model for patients with contralateral calcaneal fractures and to investigate whether the predicted lines were similar to those of the fractured calcaneus. The calcanei of five men and two women aged 44-77 years (average age, 60 years) with contralateral calcaneal fractures were analyzed. To assess the precision of the predicted fracture lines of the contralateral calcanei, they were compared with the fracture locations found by three-dimensional models of the calcanei. The fracture lines of the finite element model simulated the actual fracture lines and diagnosed joint depression types of fractures (five cases) and tongue types (two cases), but only under certain conditions for each case. This trial simulated calcaneal fractures using a patient-specific computed tomography-based nonlinear finite element model. Therefore, we suggest that it is possible to reproduce calcaneal fractures using the finite element model. It was possible to predict with precision the actual calcaneal fracture for each patient and to reproduce fracture conditions. Therefore, this method is valuable because it can provide an understanding of the pathomechanism of calcaneal fractures. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:483-489, 2019.

Prevalence and involvement patterns of radiographic hand osteoarthritis in Japanese women: the Hizen-Oshima Study.

The prevalence and pattern of joint involvement in radiographic hand osteoarthritis (OA) have been reported in Western populations, but similar data are lacking for Japanese. We examined this issue in 551 Japanese women aged > or = 40 years. Radiographs were obtained of both hands and graded according to the Kellgren-Lawrence (K-L) criteria. OA was defined as K-L grade 2 or higher. The prevalence of radiographic OA in the IP, MCP, and CMC joints was distributed similarly in both hands. The most frequent locations of radiographic OA were the distal IP joints of the index finger, the IP joint of the thumb, and the distal IP joints of the middle finger, in this order. The prevalence of radiographic OA in each joint group increased significantly with age, and that in Japanese women was lower in the thumb CMC joint and higher in the thumb IP joint compared to those in Caucasian women reported previously. The strongest predictor for the presence of radiographic OA in a particular joint was the disease status in the same joint of the opposite hand (OR = 18.5; 95% CI; 15.2-22.7), followed by the joints in the same row of the same hand (OR = 15.5; 95% CI, 11.9-20.1), and then by the joints in the same ray of the same hand (OR = 1.3; 95% CI, 1.0-1.6). Although the prevalence of hand OA is likely to show site-specific differences between Japanese and Caucasian women, our results indicate that both groups show similar involvement pattern symmetrically and in the same row of the same hand.

Nonunion of the isolated capitate waist fracture.

We report a patient with nonunion of an isolated fracture of the capitate. A male 17-year-old high school student directly hit the dorsal aspect of the carpal with the wrist in flexion position against another player's shoulder during a rugby football game. Radiographs did not show a fracture of the capitate on the day after the injury, but nonunion was distinct across the waist at the middle one-third of the capitate 4 months later. The fixation using two cannulated Herbert-Whipple screws with iliac cancellous bone graft led to sound union of the capitate and the patient's ability to return to sporting activities. Although the initial plain radiographs do not show a fracture of the capitate, we should consider the capitate fracture and check the patient by repeated physical examinations and radiographs if the patient suffers from persistent localized pain and tenderness over the capitate.